A Special Flood Hazard Area (SFHA) is FEMA's term for land with a 1% or greater annual chance of flooding — what most people call the "100-year floodplain." The 1% threshold isn't arbitrary: it's the point at which the federal government determined that mandatory flood insurance was appropriate as a condition of federally backed mortgage lending.
SFHAs appear on Flood Insurance Rate Maps (FIRMs) as the shaded areas. They're where the National Flood Insurance Program's mandatory purchase requirement applies: if you have a federally backed mortgage on property in an SFHA, you must maintain flood insurance.
Approximately 8.7 million properties in the United States are currently mapped inside an SFHA.
All flood zones beginning with A or V are Special Flood Hazard Areas:
A Zone A — 1% annual chance, no Base Flood Elevation determined
AE Zone AE — 1% annual chance with BFE determined (most common high-risk zone)
AH Zone AH — Shallow flooding (ponding), 1-3 feet deep
AO Zone AO — Shallow flooding (sheet flow), 1-3 feet deep
A99 Zone A99 — Protected by federal flood control system under construction
AR Zone AR — Flood control system under restoration
V Zone V — Coastal flooding with wave action, no BFE
VE Zone VE — Coastal flooding with wave action, BFE determined
Zones X, D, and others are not SFHAs. Zone X Shaded (500-year floodplain) and Zone X unshaded (minimal risk) don't carry mandatory insurance requirements.
Insurance requirement. With a federally backed mortgage in an SFHA, flood insurance isn't optional. Your lender will verify coverage at closing and annually. If you let your policy lapse, your lender can "force-place" insurance — purchasing a policy on your behalf at your expense, often at significantly higher cost than a policy you'd buy yourself.
Building standards. New construction and substantial improvements in SFHAs must meet the National Flood Insurance Program's floodplain management standards. The lowest floor of any new structure must be at or above the Base Flood Elevation. Utilities, HVAC, and electrical must be flood-proofed.
Disclosure requirements. Most states require sellers to disclose SFHA status to buyers. In some states, lenders must also notify borrowers. Always check the flood zone before purchasing a property.
Higher insurance premiums. SFHA designation typically means substantially higher premiums than the same structure would face outside the floodplain. How much higher depends on your specific flood zone, elevation relative to BFE, and structure characteristics.
The most direct way is to use our address lookup, which queries FEMA's National Flood Hazard Layer in real time. You'll see your flood zone designation and whether it's an SFHA.
You can also check FEMA's official Flood Map Service Center at msc.fema.gov, which allows you to view the actual Flood Insurance Rate Map for any location and download official map panels.
For definitive purposes (closing on a home, disputing insurance requirements), you'll want a certified Flood Zone Determination from a licensed provider. These are what lenders formally rely on.
Being mapped in an SFHA doesn't have to be permanent. If FEMA's map is incorrect for your specific property — your land sits higher than the map indicates — you can apply for a map amendment.
Letter of Map Amendment (LOMA) — For individual properties where the land is naturally above the Base Flood Elevation. If approved, your property is officially removed from the SFHA. The mandatory purchase requirement disappears. You can apply yourself, but hiring a licensed surveyor or engineer makes the process much smoother. Cost: $300–$700 for a survey, plus FEMA's free application process. Typical timeline: 60–90 days.
Letter of Map Revision (LOMR) — Used when physical changes have been made to the floodplain (fill, channel modifications, new levee) that reduce flood risk. More complex and expensive than a LOMA; typically requires an engineer.
A key point: even with a LOMA, purchasing flood insurance is still advisable. The LOMA removes the legal requirement; it doesn't change the underlying hydrology. Some areas successfully removed from the SFHA via LOMA have subsequently flooded.
Free instant lookup using official FEMA data